I. Alekseev
A5075534567- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Neutrino Physics Research
- Particle Detector Development and Performance
- Nuclear reactor physics and engineering
- Particle accelerators and beam dynamics
- Astrophysics and Cosmic Phenomena
- Stochastic processes and statistical mechanics
- Nuclear Physics and Applications
- Nuclear physics research studies
- X-ray Spectroscopy and Fluorescence Analysis
- Radiation Detection and Scintillator Technologies
- Advanced NMR Techniques and Applications
- Dark Matter and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Atomic and Molecular Physics
- Markov Chains and Monte Carlo Methods
- Fusion materials and technologies
- Geophysics and Gravity Measurements
- Theoretical and Computational Physics
- Solar and Space Plasma Dynamics
- Statistical Methods and Bayesian Inference
Institute for Theoretical and Experimental Physics
2015-2024
Moscow Engineering Physics Institute
2007-2024
Kurchatov Institute
2015-2024
P.N. Lebedev Physical Institute of the Russian Academy of Sciences
1999-2024
Texas A&M University
2021-2023
Joint Institute for Nuclear Research
2019-2022
National Academy of Sciences of Belarus
2022
Moscow Automobile and Road Construction State Technical University
2022
Institute of Energy Problems of Chemical Physics
2022
Moscow Institute of Physics and Technology
2016-2020
We present measurements of bulk properties the matter produced in Au+Au collisions at $\sqrt{s_{NN}}=$ 7.7, 11.5, 19.6, 27, and 39 GeV using identified hadrons ($\pi^\pm$, $K^\pm$, $p$ $\bar{p}$) from STAR experiment Beam Energy Scan (BES) Program Relativistic Heavy Ion Collider (RHIC). Midrapidity ($|y|<$0.1) results for multiplicity densities $dN/dy$, average transverse momenta $\langle p_T \rangle$ particle ratios are presented. The chemical kinetic freeze-out dynamics these energies...
We report the beam energy (sqrt[sNN]=7.7-200 GeV) and collision centrality dependence of mean (M), standard deviation (σ), skewness (S), kurtosis (κ) net-proton multiplicity distributions in Au+Au collisions. The measurements are carried out by STAR experiment at midrapidity (|y|<0.5) within transverse momentum range 0.4<pT<0.8 GeV/c first phase Beam Energy Scan program Relativistic Heavy Ion Collider. These important for understanding quantum chromodynamic diagram. products moments, Sσ κσ2,...
We report the first measurements of kurtosis (\kappa), skewness (S) and variance (\sigma^2) net-proton multiplicity (N_p - N_pbar) distributions at midrapidity for Au+Au collisions \sqrt(s_NN) = 19.6, 62.4, 200 GeV corresponding to baryon chemical potentials (\mu_B) between 20 MeV. Our products \kappa \sigma^2 S \sigma, which can be related theoretical calculations sensitive number susceptibilities long range correlations, are constant as functions collision centrality. compare these with...
We report the first measurements of moments -- mean ($M$), variance ($\sigma^{2}$), skewness ($S$) and kurtosis ($\kappa$) net-charge multiplicity distributions at mid-rapidity in Au+Au collisions seven energies, ranging from $\sqrt {{s_{\rm NN}}}$= 7.7 to 200 GeV, as a part Beam Energy Scan program RHIC. The are related thermodynamic susceptibilities net-charge, sensitive proximity QCD critical point. compare products moments, $\sigma^{2}/M$, $S\sigma$ $\kappa\sigma^{2}$ with expectations...
Global polarization of $\Lambda$ hyperons has been measured to be the order a few tenths percent in Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV, with no significant difference between and $\bar{\Lambda}$. These new results reveal collision energy dependence global together previously observed 7.7 -- 62.4 GeV indicate noticeable vorticity medium created non-central heavy-ion highest RHIC energy. The signal is rough quantitative agreement theoretical predictions from hydrodynamic model...
Nuclear collisions recreate conditions in the universe microseconds after Big Bang. Only a very small fraction of emitted fragments are light nuclei, but these states fundamental interest. We report observation antihypertritons - composed an antiproton, antineutron, and antilambda hyperon produced by colliding gold nuclei at high energy. Our analysis yields 70 +- 17 157 30 hypertritons. The measured hypertriton (antihypertriton) helium3 (antihelium3) similar, suggesting equilibrium...
Rapidity-odd directed flow (v1) measurements for charged pions, protons, and antiprotons near midrapidity (y=0) are reported in sNN=7.7, 11.5, 19.6, 27, 39, 62.4, 200 GeV Au+Au collisions as recorded by the STAR detector at Relativistic Heavy Ion Collider. At intermediate impact parameters, proton net-proton slope parameter dv1/dy|y=0 shows a minimum between 11.5 19.6 GeV. In addition, changes sign twice 7.7 39 The results qualitatively resemble predictions of hydrodynamic model with...
We report the first measurement of charmed-hadron (D(0)) production via hadronic decay channel (D(0) → K(-) + π(+)) in Au+Au collisions at sqrt[s(NN)] = 200 GeV with STAR experiment. The charm cross section per nucleon-nucleon collision midrapidity scales number binary collisions, N(bin), from p+p to central collisions. D(0) meson yields Au are strongly suppressed compared those scaled by for transverse momenta p(T) > 3 GeV/c, demonstrating significant energy loss quarks hot and dense...
Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local manifest themselves as charge separation along the magnetic field axis via chiral effect. experimental observation of previously reported for collisions at top RHIC energies. In this Letter, we present results beam-energy dependence correlations $\mathrm{Au}+\mathrm{Au}$ midrapidity center-of-mass energies 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV from...
The Λ (Λ[over ¯]) hyperon polarization along the beam direction has been measured in Au+Au collisions at sqrt[s_{NN}]=200 GeV, for first time heavy-ion collisions. dependence on hyperons' emission angle relative to elliptic flow plane exhibits a second harmonic sine modulation, indicating quadrupole pattern of vorticity component direction, expected due flow. is found increase more peripheral collisions, and shows no strong transverse momentum (p_{T}) p_{T} greater than 1 GeV/c. magnitude...
DANSS is a highly segmented 1~m${}^3$ plastic scintillator detector. Its 2500 one meter long strips have Gd-loaded reflective cover. The detector placed under an industrial 3.1~$\mathrm{GW_{th}}$ reactor of the Kalinin Nuclear Power Plant 350~km NW from Moscow. distance to core varied on-line 10.7~m 12.7~m. building provides about 50~m water-equivalent shielding against cosmic background. detects almost 5000 $\widetilde\nu_e$ per day at closest position with background less than 3$\%$....
Non-monotonic variation with collision energy ($\sqrt{s_{\rm NN}}$) of the moments net-baryon number distribution in heavy-ion collisions, related to correlation length and susceptibilities system, is suggested as a signature for Quantum Chromodynamics (QCD) critical point. We report first evidence non-monotonic kurtosis times variance net-proton (proxy number) function \rootsnn 3.1$\sigma$ significance, head-on (central) gold-on-gold (Au+Au) collisions measured using STAR detector at RHIC....
The chiral magnetic effect (CME) is predicted to occur as a consequence of local violation $\mathcal{P}$ and $\mathcal{C}P$ symmetries the strong interaction amidst electromagnetic field generated in relativistic heavy-ion collisions. Experimental manifestation CME involves separation positively negatively charged hadrons along direction field. Previous measurements CME-sensitive charge-separation observables remain inconclusive because large background contributions. To better control...
The Breit-Wheeler process which produces matter and anti-matter from photon collisions is investigated experimentally through the observation of 6085 exclusive electron-positron pairs in ultra-peripheral Au+Au at $\sqrt{s_{_{NN}}}=200$ GeV. measurements reveal a large fourth-order angular modulation $\cos{4\Delta\phi}=(16.8\pm2.5)\%$ smooth invariant mass distribution absent vector mesons ($\phi$, $\omega$ $\rho$) experimental limit $\le 0.2\%$ observed yields. differential cross section as...
We report a systematic measurement of cumulants, $C_{n}$, for net-proton, proton and antiproton multiplicity distributions, correlation functions, $\kappa_n$, distributions up to the fourth order in Au+Au collisions at $\sqrt{s_{\mathrm {NN}}}$ = 7.7, 11.5, 14.5, 19.6, 27, 39, 54.4, 62.4 200 GeV. The $C_{n}$ $\kappa_n$ are presented as function collision energy, centrality kinematic acceptance rapidity, $y$, transverse momentum, $p_{T}$. data were taken during first phase Beam Energy Scan...
The strong force, as one of the four fundamental forces at work in universe, governs interactions quarks and gluons, binds together atomic nucleus. Notwithstanding decades progress since Yukawa first developed a description force between nucleons terms meson exchange, full understanding interaction remains major challenge modern science. One remaining difficulty arises from non-perturbative nature which leads to phenomenon quark confinement distance scales on order size proton. Here we show...
The deconfined quark-gluon plasma (QGP) created in relativistic heavy-ion collisions enables the exploration of fundamental properties matter under extreme conditions. Noncentral can produce strong magnetic fields on order <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mn>10</a:mn><a:mn>18</a:mn></a:msup><a:mtext> </a:mtext><a:mtext> </a:mtext><a:mi mathvariant="normal">G</a:mi></a:math>, which offers a probe into electrical conductivity QGP. In particular,...
A systematic study is presented for centrality, transverse momentum (${p}_{T}$), and pseudorapidity ($\ensuremath{\eta}$) dependence of the inclusive charged hadron elliptic flow (${v}_{2}$) at midrapidity ($|\ensuremath{\eta}|<1.0$) in $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{NN}}=7.7$, 11.5, 19.6, 27, 39 GeV. The results obtained with different methods, including correlations event plane reconstructed a region separated by large gap four-particle cumulants (${v}_{2}{4}$), are to...
Measurements of the elliptic flow, ${v}_{2}$, identified hadrons (${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, ${K}^{\ifmmode\pm\else\textpm\fi{}}$, ${K}_{s}^{0}$, $p$, $\overline{p}$, $\ensuremath{\phi}$, $\ensuremath{\Lambda}$, $\overline{\ensuremath{\Lambda}}$, ${\ensuremath{\Xi}}^{\ensuremath{-}}$, ${\overline{\ensuremath{\Xi}}}^{+}$, ${\ensuremath{\Omega}}^{\ensuremath{-}}$, ${\overline{\ensuremath{\Omega}}}^{+}$) in $\mathrm{Au}+\mathrm{Au}$ collisions at...
We report measurements of charmed-hadron $({D}^{0},{D}^{*})$ production cross sections at midrapidity in $p+p$ collisions a center-of-mass energy 200 GeV by the STAR experiment. Charmed hadrons were reconstructed via hadronic decays ${D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$, ${D}^{*+}\ensuremath{\rightarrow}{D}^{0}{\ensuremath{\pi}}^{+}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}$ and their charge conjugates,...
We report the first measurement of elliptic anisotropy (v_{2}) charm meson D^{0} at midrapidity (|y|<1) in Au+Au collisions sqrt[s_{NN}]=200 GeV. The was conducted by STAR experiment RHIC utilizing a new high-resolution silicon tracker. measured v_{2} 0%-80% centrality can be described viscous hydrodynamic calculation for transverse momentum (p_{T}) less than 4 GeV/c. as function kinetic energy (m_{T}-m_{0}, where m_{T}=sqrt[p_{T}^{2}+m_{0}^{2}]) is consistent with that light mesons 10%-40%...
We report measurements of the third harmonic coefficient azimuthal anisotropy, ${v}_{3}$, known as triangular flow. The analysis is for charged particles in Au+Au collisions at $\sqrt{{s}_{\mathit{NN}}}=200$ GeV, based on data from STAR experiment BNL Relativistic Heavy Ion Collider. Two-particle correlations a function their pseudorapidity separation are fit with narrow and wide Gaussians. Measurements flow extracted Gaussian, two-particle cumulants gap, also event plane methods large gap...
We report new STAR measurements of mid-rapidity yields for the $\Lambda$, $\bar{\Lambda}$, $K^{0}_{S}$, $\Xi^{-}$, $\bar{\Xi}^{+}$, $\Omega^{-}$, $\bar{\Omega}^{+}$ particles in Cu+Cu collisions at \sNN{200}, and $K^{0}_{S}$ Au+Au \sNN{200}. show that a given number participating nucleons, production strange hadrons is higher than same center-of-mass energy. find aspects enhancement factors all can be described by parameterization based on fraction participants undergo multiple collisions.